Production of antioxidants for fatty materials



Patented Feb. l5,

P BODUCTIONQF ANTIOXIDANTS FOR FATTY MATERIALS tion of New Jersey NoDrawing. Application March 16, 1946, Serial No. 655,009

The present invention relates to the stabilization of fatty materials.More particularly, the

present invention relates to the preservation and stabilization of fattymaterials such as fish liver oils or the like against oxidation.

In U. S. patent application Serial No. 431,700, filed February 20, 1942,now U. S. Patent No. 2,396,680, there are disclosed antioxidantconcentrates which can be prepared from various types of oils which areparticularly applicable for the stabilization of fatty materials.

It has now been discovered that if antioxidants of the characterdescribed in the aforementioned patent are added to a fatty material andsimultaneously, or thereafter, the mixture of fatty material andantioxidant is treated with ammonia, the antioxidant effect is greatlyenhanced, Furthermore, the antioxidant concentrates can be treated withammonia and thereafter the ammonia-treated concentrates can be added tofatty materials. In other words, the stabilized fatty material, afterstanding for a substantial time, will lose less of its vitamin value andwill be less susceptible to oxidation if the material is combined withan antioxidant and then treated with ammonia, or if the antioxidant istreated with ammonia and thereafter added to the fatty material. It isbelieved that this is due to the formation in situ of new antioxidantsubstances both in the antioxidant concentrate and in the fattymaterial. In some instances these substances may be produced fromcomponents of the fatty material which, prior to ammonia treatment, haveno antioxidant value. In addition to these antioxidants, 'neW and betterantioxidant components are believed to be produced from the antioxidantconcentrate disclosed in the aforementioned application.

It is, therefore, one of the objects of the present invention tostabilize various types of fatty materials against oxidation. /7

A second object of the present invention is to stabilize the vitaminvalues of fatty materials containing the same, as, for example, fishliver oils, by the addition ofan antioxidant concentrate to the fishliver oil and thereafter treatin the same with ammonia.

A third object of the invention is to form new antioxidant concentratesby treating antioxidant concentrates with ammonia.

Other objects and advantages of the present invention will becomeapparent from the subsequent specification and claims.

The present invention can be applied to various types of fatty materialssuch as fatty oils, fats,

8 Claims. (Cl. 167-81 waxes, soaps, vitamin concentrates, etc. Thus,

.oils and fats of animal, vegetable or fish origin,

such as cod liver oil, as well as vitamin concentrates orvitamin-containing fractions obtained from such oils; corn oil,cottonseed oil, soybean oil, and other vegetable oils; fats such asbutter, margarine, lard, hydrogenated shortenings, palm oil, etc; soapsof higher fatty acids; and compositionscontaining such fatty materialsas essential ingredients, as, for example, cookies, cakes, crackers,breakfast cereals, etc., as well as food emulsions such as mayonnaise;may all be suitably stabilized in accordance with this invention.Furthermore, substances such as sulfonated oils and other sulfonatedfatty compounds, amides, monoand diglycerides and other fatty substanceswhich tend to become rancid upon exposure to air may be treated inaccordance with the present invention. Other materials subject to changeupon oxidation which can be treated include cosmetics such as facecreams, hand lotions, shaving creams, etc; gasoline, mineral oil,lubricating oils, rubber,

etc. The amount of the extract added to the material to be stabilizedmay vary considerably depending upon the activity of the extract and thedegree of instability of the material to be stabilized. In general, fromabout 0.1% to about 20%, preferably from about 0.5% to about 5%, ofantioxidant extract may be added to the oil or fat.

The present process is particularly applicable to the stabilization offat-soluble vitamin-containing oils or concentrates as well asvitamincontainingfractions recoverable from such products by vacuumdistillation, solvent extraction or other processes.

Substances of a fatty nature stabilized in accordance with the presentinvention can be heated to elevated temperatures without substantiallyaifecting the activity of the antioxidants; moreover, the heating ofvitamin-containing oils so stabilized does not substantially reduce thevitamin activity of the oils.

The present process is applicable to antioxidant concentrates which areproduced by solvent extraction from crude vegetable oils and similartypes of oils containing relatively large proportions of antioxidant.Thus, vegetable oils and fats such as soybean oil, wheat germ oil, corngerm oil, corn oil, oat oil, rye oil, olive oil, sesame oil, cottonseedoil, palm oil, cocoa butter, palm kernel oil, coconut oil, rice oil,rice germ oil, linseed oil, citicia oil, teaseed oil, perilla oil,alfalfa oil, celery seed oil, flax seed oil, groundnut oil, hempseedoil,

3 kapok oil, mustard seed oil, rapeseed oil, poppy seed oil, sunflowerseed oil, pumpkin seed oil, melon seed oil, peanut oil and the like canbe treated. Another group of fatty materials which can be employed arethe fish liver oils such as cod liver oil, tuna liver oil, halibut liveroil, shark liver oil, etc., as well as other marine oils such asmenhaden oil, herring oil and sardine oil. Other oils which can betreated in accordance with my invention are tomato seed oil, grape seedoil, peach kernel oil, egg oil and whale oil. Preferably, theantioxidants are produced from vegetable oils.

Solvents which can be used in carrying out the process of the inventioninclude isopropyl alcohol, n-propyl alcohol, acetone, diacetone alcohol,ethyl acetate, methyl acetate and methyl ethyl ketone, said solventscontaining at least of water. The natural antioxidants which it isdesired to extract from the fatty materials are soluble in thesesolvents at room temperature (10 to 30 C.) whereas the fatty materialsthemselves are immiscible therewith or relatively so. While thesesolvents have proved to be very successful in the practice of thisinvention, it is highly preferred to use aqueous isopropanol andparticularly 85% to 90% isopropanol.

In carrying out the extraction of the antioxidants from the oils withwhich they are associated, the oil to be treated is first mixed with theparticular solvent to be employed. The relative proportion of oil tosolvent may vary widely; the ratio of solvent to oil should be greaterthan one, and, preferably, two to fifty parts of solvent to one part ofoil. If desired, the solvent-oil mass may be warmed to a temperatureslightly or substantially above room temperature. By so doing it issometimes possible to obtain somewhat more intimate contact of thesolvent with the fatty material and thereby obtain a more efficient andcomplete extraction of the natural antioxidants. The solvent solutionand the fatty material can then be separated from each other at theelevated temperature or the mixture can first be allowed to cool to roomtemperature before completing this step of the process. The extractionis preferably carried out in an atmosphere of inert gas.

The antioxidant fraction extracted from the oil may be recovered in anysuitable manner. As the solvent and the oil are immiscible at room or attemperatures substantially above room temperature, they can be separatedby decantation, centrifugation or any other suitable means. The oil willgenerally be found to be somewhat lighter in color than originally andin many cases will have lost some of its original characteristic odor.Furthermore, in .most cases it will be found that materials responsiblefor producing break have been removed from the oil by the extraction.Thus the oil which has been extracted by the process of this inventioncan be used for a wide variety of purposes in accordance with processeswell known to the art.

The solvent solution can be filtered and then treated to remove thesolvent therefrom, e, g., by vacuum distillation, whereby an extract isrecovered containing relatively large amounts of highly activeantioxidants. If desired, water may be added to the extract in order toprecipitate some of the glycerides contained therein or some of thesterols may be removed; however, these steps are not essential since theglycerides erties of the extract. If the extract contains an excessiveamount of free fatty acids, these are preferably removed by treatmentwith alkali in a hydrocarbon or chlorinated hydrocarbon solvent mediumor by other suitable methods. The extract ordinarily possesses thecharacteristic odor and color of the oil from which it is obtained andis generally slightly more viscous than the original oil. Tests carriedout on vegetable oil extracts indicate that the iodine values of theextracts are substantially lower than those of the original oils. If avitamin-containing fish liver oil is employed in the practice of thepresent invention, it will be found that the extract contains aconsiderable portion of the vitamins concentrated therein.

Preferably, the fish liver oil and the like, hav-- ing an antioxidantconcentrate of the character previously set forth added thereto, istreated with ammonia in the presence of a suitable solvent for the fishliver oil. Similarly, when an antioxidant concentrate is first treatedwith ammonia, a suitable solvent is preferably used. The solventemployed in the practice of this in.- vention should be one in which thefatty material to be stabilized is readily soluble and/or theantioxidant concentrate is at least partially soluble. Thus, if a fishliver oil or concentrate prepared therefrom is being treated, ahydrocarbon or halogenated hydrocarbon solvent such as hexane, heptane,octane, ethylene dichloride, trichlorethylene, carbon tetrachloride,cyclohexnae, methyl cyclohexane or benzene may be employed as thesolvent, as well as solvents such as acetone, diacetone alcohol, and thelike. Further, mixtures of the above solvents may also be used. Thus amixture of equal parts of acetone and methanol has beeii'foundespecially suitable.

The amount of solvent employed should be at least equivalent to and, insome instances, in excess of the amount of material being treated. Theamount of ammonia used in the process is relatively small as compared tothe quantity of fatty material or fish liver oil being treated and mayvary from about 1% to 20% by weight of concentrated aqueous ammonia ascompared to the weight of the fatty material. When gaseous ammonia orliquid ammonia is used, the amount is equivalent to that quantity ofconcentrated aqueous ammonia above set forth. It is to be understoodthat liquid or gaseous ammonia may be used in the present process. It isdesired to point out, therefore, that when in the specification andclaims the term ammonia is used, liquid or gaseous ammonia and ammoniadissolved in water or other suitable solvent therefor is intended, Ingeneral, the quantity of antioxidant concentrate which is added to thefish liver oil and the like is relatively small, being in theneighborhood of 2%, although in some instances from 0.1%to 20% may beused. Preferably, however, from 0.5% to about 5% of antioxidantconcentrate is sufficient to greatly enhance the stability of fattymaterials of the character set forth.

It may be noted that where the antioxidant concentrate or extract istreated with ammonia before being added to the fatty material to bestabilized, the amount of ammonia used is equivalent to that just setforth, i. e., approximately equal to and in some instances considerablyless than the weight of the concentrate.

The following examples are intended to illustrate the invention withoutin any way limiting the same:

aeensos Example I 500 grams of crude corn oil were admixed with 2000 ml.of 88% aqueous isopropanol and the mixture warmed to 50 C. in thepresence of nitrogen gas. The mass after reaching 50 C. was agitated andthen cooled to room temperature after which the solvent solution of theextracted material was separated from the oil. The oil was againextracted in the manner set forth above and the two extracts combinedand freed of isopropanol and water under reduced pressure in thepresence of gaseous nitrogen. The yield of antioxidant extract was 55grams.

25 grams of a carbon-refined shark liver oil having a potency of 56,400U. S. P. units of vitamin A per gram and containing .75 gram of theextract recovered above were dissolved in 100 cc. of acetone. 5 cc. ofconcentrated (28%) ammonlum hydroxide were added to the acetone solutionand the mass was refluxed for three hours. The acetone, ammonia andwater were then removed from the mass by distillation under reducedpressure.

Example I! 200 grams of crude corn oil were admixed with 800 ml. of 85%aqueous isopropanol and the mixture warmed to 50 C. in the presence ofnitrogen gas. The mass after reaching 50 C. was agitated and then cooledto room temperature after which the solvent solution of the extractedmaterial was separated from the oil. The oil was again extracted in thesame manner set forth above and the two extracts combined and freed ofisopropanel and water under reduced pressure in the presence of gaseousnitrogen. The yield of antioxidant extract was 14.8 grams.

25 grams of a carbon-refined shark liver oil having a potency of 56,400U, S. P. units of vitamin A per gram and containing .75 gram of theextract recovered above were dissolved in 100 cc. of acetone. 5 cc. ofconcentrated (28%) ammonia hydroxide were added to the acetone solutionand the mass was refluxed for three hours. The acetone, ammonia andwater were then removed from the mass by distillation under reducedpressure. 1

The stabilized products produced according to Examples I and II werecompared with a blank of the same carbon-refined shark liver oil, asecond blank of the same oil containing 3% of the 88% aqueousisopropanol extract per se, and a third blank of the same oil containing3% of the 85% aqueous isopropanol extract per se, produced according tothe first half of Examples I and II, respectively, by pouring 20 gramsof each oil in a separate 100 cc. beaker and storing these samples at 36C. in a dark oven. The vitamin A potency in each sample was measured atintervals as revealed in the following table:

Table Per Cent Loss of Vitamin A Alter sample Gdsys l4days 20days lCarbon-refined shark liver oil containing 56,400 A/gm 51.0 2 Sample (1)containing 3 88% aqueous isopropanol extract 7. 3 26. 8 45. 5 3 Sample(ll containing 3% 85% aqueous isopropanol extract 6. 6 26. O 43. 2 4Product of Example I... 5.0 12.0 18.0 5 Product of Example II 5.0 17. 827. 2

It will be noted that the process may also be .practlced by firsttreating an antioxidant concentrate of the character set forth with asmall amount of ammonia in the presence of a solvent in which theantioxidant concentrate is at least partially soluble. Thereafter the soactivated antioxidant concentrate may be added to the fatty materialprone to oxidation.

This application is a continuation-in-part of our application Serial No.528,353 flied March 27, 1944, now Patent No. 2,434,790.

Having described our invention, what we claim as new and desire tosecure by Letters Patent is:

l. A process for producing an antioxidant for stabilizing fattymaterials which comprises contacting a crude fatty material containingnatural antioxidants with a solvent selected from the group consistingof isopropanol, n-propanol, acetone, diacetone alcohol, ethyl acetate,methyl acetate and methyl ethyl ketone, said solvents containing atleast 10% of water, separating a solution containing a highly activeantioxidant extract from the remainder of the fatty material, recoveringthe antioxidant extract from the solvent solution thereof and contactingsaid extract with ammonia to increase its antioxidant activity.

2. The process of claim 1 wherein the antioxidant extract is contactedwith ammonia while dissolved in a fat solvent.

3. A process for stabilizing a. fatty material prone to oxidation whichcomprises adding to the fatty material an antioxidant extract-producedby contacting a crude fatty material containing natural antioxidantswith a solvent selected from the group consisting of isopropanol,

n-propanol, acetone, diacetone alcohol, ethyl acetate, methyl acetateand methyl ethyl ketone, said solvents containing at least 10% of water,separating a solution containing a highly active antioxidant extractfrom the remainder of the fatty material and recovering the antioxidantextract. from the solvent solution thereofand contacting said fattymaterial containing said added antioxidant extract with ammonia toincrease the antioxidant activity of said extract.

4. The process of claim 3 wherein the fatty material containing theantioxidant extract is contacted with ammonia while dissolved in a fatsolvent.

5. The process of claim 3 wherein the fatty material containing theantioxidant extract is contacted. with ammonia while dissolved inacetone.

6. A process for stabilizing a fatty material containing a fat-solublevitamin which comprises adding to the fatty material an antioxidantextractproduced by contacting a crude fatty material containing naturalantioxidants with a solvent selected from the group consisting ofisopropanol, n-propanol, acetone, diacetone, alcohol, ethyl acetate,methyl acetate and methyl ethyl ketone, said solvents containing atleast 10% of water, separating a solution containing a highly activeantioxidant extract from the remainder of the fatty material andrecovering the antioxidant extract from the solvent solution thereof-andcontacting said fatty material containing said added antioxidant extractwith ammonia to increase the antioxidant activity of said extract.

7. The process of claim 6 wherein the fatty material containing theantioxidant extract is contacted with ammonia while dissolved in a fatsolvent.

8. The process of claim 6 wherein the fatty 8 material containing theantioxidant extract is UNIT contacted with ammonia while dissolved in EDSTATES PATENTS acetone. Number Name Date LORAN o. ZBUX'I'ON, 09 WilhelmOct. 1, 1929 CHARLES E. DRYDEN. 5 2,263,736 1101! Jan. 6, 1942 2,396,680Buxton Mar. 19, 1946 REFERENCES CITED.

The following references are of record in the file of this patent:

